Power Generation System for Transportation

The present invention relates to a power generation system for transportation, and more particularly, to a power generation system installed in a brake disc device for a vehicle.

Among transportation vehicles, trailers are vehicles that are connected to a tractor (towing vehicle) to carry cargo or people without power. They are largely divided into commercial trailers and camping trailers. Commercial trailers need power (electric energy) for indoor lights, tailgate, refrigerators, etc., and camping trailers need power to operate home appliances such as indoor and outdoor lights, TVs, and refrigerators.

Currently, the power for the trailer is either from the tractor battery or generated by a diesel generator installed separately on the trailer.

On the other hand, if the power of the tractor battery is used, some modifications to the tractor are required in the process of installing the power supply line. If a diesel generator installed separately on the trailer is used, maintenance such as frequent diesel fuel injection and lubricant injection are required, and there are various restrictions on the installation and operation of the diesel generator due to the limited internal space of the trailer. In addition, there is the problem of noise and harmful gases being generated while the diesel generator is in operation.

Accordingly, an objective of the present invention is to provide a power generation system that self-generates electricity required by a transportation vehicle, such as a trailer.

One aspect of the present invention to achieve the foregoing objectives is a power generation system for transportation, the power generation system comprising: an axle; a brake disc having a space in a center; a brake pad for applying braking force to the brake disc; a rotor installed on an inner surface of the space to face the axle and having a plurality of permanent magnets; a stator installed on an outer surface of the axle to face the rotor and having a coil; and a dust shield installed in a path between the brake pad and the rotor to shield dust from the brake pad.

Preferably, the dust shield prevents the pad dust from entering a gap between the rotor and the stator.

Preferably, the dust shield comprises a sleeve, an O-ring, and a seal. The sleeve has a groove and is installed in front of the rotor. The sleeve is directly or indirectly fixed to the stator so as not to rotate with the rotation of the brake disc. The O-ring and the seal are installed in close contact with the groove of the sleeve. The seal slides in contact with the brake disc when the brake disc rotates.

The present invention adopts a self-generation method in which a generator is installed in a space provided in a brake disc device of a transportation vehicle such as a trailer to directly supply the necessary electric energy, thereby eliminating power-related problems of conventional trailers.

In addition, the present invention not only greatly increases the space utilization of the transportation vehicle, but also eliminates the need for separate wiring work to supply power from other vehicles such as tractors. Furthermore, since the present invention does not require a diesel generator, there is no noise or harmful gas generated by the installation and operation of a diesel generator, and maintenance costs are greatly reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiments of the present invention, identical elements are described with identical reference numerals as much as possible in the drawings. Specific descriptions of the configuration or function of related known technologies may be omitted so as not to obscure the gist of the present invention. In addition, the matters expressed in the accompanying drawings are diagrammatically illustrated for the purpose of easily explaining the embodiments of the present invention and may differ from the form actually implemented.

1 FIG. 2 FIG. 1 FIG. 3 FIG. 2 FIG. 1 1 3 6 10 3 1 3 1 is a cross-sectional view of a power generation systemaccording to an embodiment of the present invention. As illustrated, the power generation systemincludes an axle, a brake disc, and a generator.is a detailed cross-sectional view parallel to the longitudinal direction of the axleof the power generation systemillustrated in, andis a cross-sectional view perpendicular to the longitudinal direction of the axleof the power generation systemillustrated in.

3 2 5 6 3 4 7 6 7 6 The axleis fixed to a chassisof a vehicle (e.g., a trailer). A wheel hub, together with the brake disk, is installed on the outer surface of the axlevia a plurality of bearingsand rotates passively. A spaceis formed in the center of the brake disc. The spacemay be recessed into one side surface of the brake disk.

10 8 9 8 7 3 8 8 8 7 6 8 7 6 6 9 3 8 9 9 9 9 9 9 9 9 9 3 11 8 9 8 9 a a a a b b a b a a a The generatorhas a rotorand a stator. The rotoris installed on the inner surface of the spaceso as to face the axleand has a plurality of permanent magnets. The rotormay be in the form of a ring in which a plurality of permanent magnetsare arranged at equal intervals and are closely fixed to the inner surface of the spaceof the brake disc. Since the permanent magnetsare closely fixed to the inner surface of the spaceof the brake disc, they rotate along the brake disc(or wheel). The statoris fixed to the outer surface of the axleopposing the rotor. The statoris configured by winding stator coilsaround a yoke. The yokeis configured by laminating a plurality of thin iron plates, and three stator coilsare wound around the yoke. One phase of alternating current is induced in each of the three stator coils, so that three phases of alternating current are induced overall. The stator coilsmay be a Y-connected structure having a high line-to-line voltage. The stator coilsmay be wired into the interior of a vehicle (e.g., a trailer) through a hole formed in the longitudinal direction of the axle. A predetermined gapis formed between the rotorand the stator, so that the rotorand the statorare close to each other but do not touch each other.

8 8 7 6 8 9 9 9 9 10 10 a a b A rotorcomposed of a plurality of permanent magnetsarranged in a ring shape is installed in the spaceof a brake discand generates a rotating magnetic field when it rotates. When the rotating magnetic field generated by the rotoris linked to the statorcomposed of the stator coilsand the yoke, electric power is generated in the stator. The generatormay be a permanent magnet synchronous generator. In addition, the generatormay be a brushless synchronous generator. The permanent magnet synchronous generator (PMSG) has an efficiency that is about 90% higher than that of a general induction generator by using permanent magnets, and has the advantage of being compact and lightweight, and being able to operate at low speeds because it does not have gears.

4 FIG. 5 FIG. 4 FIG. 10 20 is a block diagram of an electric circuit according to an embodiment of the present invention, andis a circuit diagram of the generatorand the rectifiershown in.

10 20 20 1 2 3 4 5 6 10 1 2 3 4 5 6 5 FIG. The three-phase AC power output from the generatoris converted into DC power by the rectifier. As shown in, the rectifierincludes diodes D, D, D, D, D, Dand a smoothing capacitor C. The three-phase AC power output from the three-phase stator coils (phA, phB, phC) of the generatoris rectified by a plurality of full-wave diodes D, D, D, D, D, Dand then smoothed by the smoothing capacitor C, thereby outputting a DC voltage V+ to both terminals of the capacitor C to drive a DC load LOAD.

40 30 50 40 50 60 70 The DC power can be charged to the batteryby the charge control unitand then supplied to the DC load. The power of the batterycan be converted into AC power ofto 60 Hz by the inverterand then supplied to the AC load.

30 20 60 40 60 50 50 The charge control unitmay include a constant voltage unit and/or a constant current unit. The constant voltage unit and/or the constant current unit stabilizes the DC power output from the rectifier. The invertermay output three-phase AC power and single-phase AC power simultaneously or alternatively. The outputs of the batteryand the inverterare each provided with terminals or outlets for connecting two or more loads, such that two or more AC loadsand DC loadsmay be connected.

10 6 8 8 9 a a a. The phase voltage, phase current, and output power of the generatorare determined by the rotational speed of the brake disk(or the rotational speed of the permanent magnets), the magnetic force intensity of the permanent magnets, and the number of turns of the stator coils

6 FIG. 2 FIG. 7 FIG. 8 FIG. 1 6 1 1 is a graph illustrating the output power of the power generation systemshown in. It shows that an average power of 1,291 W was obtained when the rotation speed of the brake discwas 400 rpm.shows that a phase voltage of 220 V was obtained from the power generation system.shows that a phase current of 2.7 A was obtained from the power generation system.

5 6 5 6 8 7 9 10 20 40 30 40 50 60 70 a a For example, when a trailer is towed by a tractor, the wheel (or wheel hub) rotates, and the brake discfixed to the wheel hubrotates in conjunction. As the brake discrotates, the permanent magnetsinstalled in the spacerotates to generate a rotating magnetic field, which in turn generates an induced voltage in the stator coils. The AC power generated from the generatoris converted into DC power by the rectifierand then charged to the batteryby the charge control unit. The DC power charged to the batteryis supplied to multiple DC loadsof the trailer, or is converted into AC power by the inverterand supplied to multiple AC loads.

19 7 6 For example, it is desirable for the generatorto be installed in each central spaceof multiple brake disksinstalled in the trailer to generate sufficient power.

9 FIG. 10 FIG. 9 FIG. 11 FIG. 9 FIG. 9 FIG. 102 100 100 100 102 104 105 110 105 108 106 is a cross-sectional view parallel to the longitudinal direction L of the axleof the power generation systemaccording to another embodiment of the present invention.is an enlarged view of portion A shown in, andis a schematic diagram of a part of the power generation systemshown in. As shown in, the power generation systemhas an axle, a brake disc, a generator, and a tone wheel. The generatorhas a rotorand a stator.

104 109 108 109 102 106 102 108 110 104 110 102 110 104 100 112 110 112 The brake dischas a spacein the center. The rotoris installed on the inner surface of the spaceso as to face the axleand has a plurality of permanent magnets. The statoris installed on the outer surface of the axleso as to face the rotorand has coils. A tone wheelis installed on one side of the brake disc. The tone wheelhas exciter teeth and is installed so that the front face faces the longitudinal direction L of the axle. The tone wheelmay be formed integrally with the brake disc. The power generation systemfurther has a wheel speed sensorso as to face the tone wheel. The wheel speed sensorsenses the rotational speed of the wheel by detecting changes in the magnetic field as the wheel rotates.

100 108 110 100 108 112 108 112 110 112 110 112 The power generation systemfurther includes a magnetic flux controller for suppressing the magnetic flux of the permanent magnets constituting the rotorfrom being transmitted to the tone wheel. The power generation systemhas an advantage in that it can be configured very compactly since the rotorand the wheel speed sensorare positioned inside the brake device or very close to the brake device. However, there is a concern that the magnetic flux of the permanent magnets constituting the rotormay affect the wheel speed sensorvia the tone wheel, causing the wheel speed sensorto malfunction. The magnetic flux controller suppresses the magnetic flux of the permanent magnets from being transmitted to the tone wheel, thereby allowing the wheel speed sensorto operate normally.

104 108 110 110 In this embodiment, the magnetic flux controller is implemented as a groove formed in the brake discbetween the rotor(or permanent magnets) and the tone wheel. Meanwhile, an electromagnetic shield can be used as magnetic flux controller. The electromagnetic shield can be made of a magnetic material (iron, nickel, cobalt, etc.) or a conductive material (copper, aluminum, etc.) that can suppress the magnetic flux of the permanent magnets from being transmitted to the tone wheel.

114 116 104 116 116 116 108 203 108 106 203 100 108 106 When pneumatic, hydraulic, or the like is applied, the caliper assemblypresses the brake padsagainst the brake discto generate braking force. In the process of generating braking force, the brake padsare worn. Since the brake padsinclude a metal component attracted to the permanent magnets, the pad dust generated by the wear of the brake padis attracted to the permanent magnets of the rotor. As a result, a small gapbetween the rotorand the statormay be filled with pad dust. If the gapis filled with pad dust, the power generation systemmay experience serious malfunction due to mechanical friction, electrical connection, etc. between the rotorand the stator.

100 204 204 116 108 203 204 205 206 208 205 108 205 106 104 206 208 205 208 206 208 104 104 203 To solve the above problem, the power generation systemmay further include a dust shield. The dust shieldis installed in a path between the brake padsand the rotorto shield pad dust, thereby preventing pad dust from entering the gap. The dust shieldof this embodiment includes a sleeve, an O-ring, and a seal. The sleevehas a groove and is installed in front of the rotor. The sleeveis directly or indirectly fixed to the stator, so that it does not rotate according to the rotation of the brake disc. The O-ringand the sealare installed in the groove of the sleeve. The sealis installed in close contact with the O-ring. The sealslides in close contact with the brake discwhen the brake discrotates. This configuration effectively prevents pad dust from entering the gap.

12 FIG. is a network diagram illustrating system monitoring in an embodiment of the present invention.

100 20 20 40 30 100 100 105 40 30 100 20 40 30 304 306 302 304 306 308 308 The AC voltage generated in the power generation systemis provided to the rectifier. The rectifierconverts the AC voltage into a DC voltage and provides the DC voltage to the battery. The charge control unitreceives status information of the power generation systemfrom various sensors. This status information includes the amount of power generated by the power generation system, the temperature of the generator, a fault signal, the status of the battery, etc. The charge control unitcontrols the power generation system, the rectifier, the battery, etc. using the received status information. In addition, the charge control unittransmits the status information to an in-house computer serverand/or a cloud servervia a wireless communication network. Wireless communication methods include Wi-Fi, Bluetooth, LTE, 5G, etc. The in-house computer serverand/or the cloud servergenerates a real-time monitoring signal using the transmitted status information and transmits it to the driver. The monitoring signal transmitted to the driveris used through the dashboard, smartphone app, etc. The present invention described above is not limited to the embodiments and the attached drawings, and various substitutions, modifications, and changes are possible within the scope that does not depart from the technical spirit of the present invention. This will be obvious to those skilled in the art to which the present invention belongs.